He threw just 2.2 innings for the Red Sox in 2016, before having his season ended by Tommy John surgery on May 24th. He’s approximately nine months into his recovery right now, so we shouldn’t expect to see him pitch until mid-May, but Carson Smith has the potential to be an x-factor for the bullpen.
Acquired in a trade with the Seattle Mariners last year, the Red Sox dealt Wade Miley and reliever Jonathan Aro in exchange for Roenis Elias and Smith. Neither Aro nor Elias have made an impact at the major league level, while Miley pitched 166 innings between the Mariners and Baltimore Orioles with a 5.37 ERA and 0.1 WAR. Even though Smith missed the entirety of 2016, the Red Sox are still coming out on top in this deal.
Last season was a wash, but the Red Sox acquired a 27-year-old reliever with a career 194 ERA+ and 2.11 FIP for a replacement level starter. With the depth the Sox already have in the bullpen, John Farrell can afford to ease him back into action and protect him by pitching in spots where he’s most effective. He held right-handed batters to a .167 average in 2015, with an xFIP of 1.77. In Carson Smith, the Red Sox have a great relief pitcher, with four years of team control, but is injury prone because of an unorthodox delivery.